The key technologies for drilling in goaf were elaborated in the construction of ventilation holes by raise boring in the slow inclined shaft in Laoshidan coal mine. In view of the characteristics of large diameter ventilation holes passing through the goaf, deep wells and large diameters of the shaft, the large diameter raise boring process was adopted; the pilot holes were drilled with wireless directional drilling technology, and then the orientation technology of non-magnetic single point inclinometer DTH hammer was followed; the special treatment of the pipe bottom was carried out by the technical casing isolation method to ensure the smooth lifting of the technical casing; cementation of free casing and the large diameter casing artificial flexible bottom were also employed, etc. The large diameter raise boring technology is comprehensively introduced, with the problem and achievements in the raise boring process summarized. It has a demonstration effect for similar construction.